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Updated: Jul 25, 2026
10:46
Dissection of Enhancer Function Using Multiplex CRISPR-based Enhancer Interference in Cell Lines
Published on: June 2, 2018
A factor discriminating between the wild-type and a mutant polyomavirus enhancer.
Nature
|July 2, 1987
Summary
Polyomavirus enhancer function in mouse cells is linked to specific protein binding. Mutations in the enhancer create binding sites for a factor that enables function in embryonal carcinoma cells.
Area of Science:
- Molecular Biology
- Virology
- Genetics
Background:
- Enhancers regulate gene transcription initiation through protein binding.
- Polyomavirus early gene expression differs between differentiated and undifferentiated mouse cells (embryonal carcinoma cells).
- Mutations within the polyomavirus enhancer dictate its host cell range.
Purpose of the Study:
- To investigate the molecular basis for altered polyomavirus enhancer function in embryonal carcinoma cells.
- To identify proteins interacting with wild-type and mutant polyomavirus enhancer sequences.
Main Methods:
- Assaying protein extracts from embryonal carcinoma cells for binding to polyomavirus enhancer sequences.
- Utilizing transfection assays with wild-type and mutant enhancers to assess host range.
Main Results:
- A protein was detected that binds to a mutant enhancer sequence (F441) but not to the wild-type sequence.
- This binding difference correlates with the enhancer's ability to function in embryonal carcinoma cells.
Conclusions:
- The sequence alteration in the F441 mutant likely created a binding site for a positive regulatory factor.
- This factor enables polyomavirus enhancer function in undifferentiated embryonal carcinoma cells, explaining the observed host range difference.
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